The present invention relates to sustained release fragrance accords wherein the initial fragrance release or bouquet is not distorted by the presence of an unbalanced accord. The systems of the present invention comprise fragrance raw materials and one or more pro-fragrances and/or pro-accords which provide enhanced longevity of the initial fragrance accords.
The art relating to pro-accords and pro-fragrances has recently been advanced to the point where a single molecule is capable of releasing a mixture of fragrance raw materials. By manipulation of the pro-accord or pro-fragrance structure, inter alia, acetal, ketal, orthoester, the formulator is now capable of delivering any class of fragrance raw material, inter alia, aldehydes, ketones, alcohols. In addition, by selecting the secondary structure of the pro-accord or pro-fragrance, the formulator can control the rate of fragrance release and the conditions under which said release will be sustained.
The initial impression imparted by fully formulated fragrances and accords is an important aesthetic attribute and provides the user with a display of the fragrance which will be imparted to others as they come into contact with the user. This initial impression is typically delivered to a situs, inter alia, skin which frequently has no other scents or fragrances to interfere with the character of the accord.
However, due to differential evaporation of the various perfume components, fully formulated fragrances (accords) have an initial fragrance profile which is different from the fragrance profile once the perfume top notes have begun to evaporate. The deliberate replenishment of these depleted top notes, together with any depleted lesser volatile middle and base notes, by pro-fragrances and pro-accords provides a first step in ameliorating the gradual change over time of the initial fragrance profile. However, use of pro-fragrances and pro-accords can contribute, in combination with free fragrance raw materials, to a distorted initial fragrance impression.
There exists no method or system by which the formulator can overcome this initial fragrance distortion. There is a long felt need for a process and a means for determining in which quantities fragrance raw materials, inter alia, initial fragrances or accords, and the pro-fragrances or pro-accords from which these components are released need to be admixed to supply a non-distorted initial fragrance impression. There is also no fragrance delivery system which allows the formulator to deliver a perfume accord which is balanced at the time of application and remains so over an extended period of time.
The present invention meets the aforementioned needs in that a fragrance delivery system and a method for determining the relative concentrations of ingredients necessary to provide both a balanced initial and sustained accord impression has been surprisingly discovered. By employing the steps described herein the formulation of balanced delivery systems can now be accomplished. The formulator can now employ any number of pro-accords or pro-fragrances to deliver a sustained fragrance character or a differential fragrance character. The initial fragrance impression is not distorted by the system of the present invention regardless of which point in use or delivery the system components are deployed, inter alia, pre-mixed, combined in a chamber, at said situs of contact or use.
The first aspect of the present invention relates to a fragrance delivery system comprising:
a) a pro-fragrance component comprising:
i) P number of a pro-fragrance, a pro-accord, or mixtures thereof, which together release i number of fragrance raw materials, fi, the index i identifies a particular fragrance raw material and the corresponding parameters, and at least a number j of said fragrance raw materials, fi, satisfies the boundary condition defined by:
"khgr"i greater than n(vDi)
xe2x80x83wherein "khgr"i is 100% of the amount of the ith fragrance raw material, fi, which is releasable from all of said pro-fragrances or pro-accords which are capable of releasing said ith fragrance raw material; vDi is the odor detection concentration of an ith fragrance raw material, whereby j number of said fragrance raw materials, fi, satisfy said boundary condition; P is at least 1; i is at least 1; j is at least 1; n is a multiple of the odor detection concentration and is equal to at least 1;
ii) optionally fragrance raw material release modifiers; and
b) a free fragrance component comprising:
i) an initial amount, xcex5i, of said j number of ith fragrance raw materials, fi, which satisfy the boundary condition defined in (a); wherein xcex5i of said ith fragrance raw material is defined as:
xcex5ixe2x89xa6a("khgr"i)
a is 10;
ii) optionally the balance one or more other fragrance raw materials, carriers, and adjunct ingredients.
The present invention further relates to compositions comprising the herein described fragrance delivery systems.
Another aspect of the present invention relates to a process for forming the fragrance delivery systems of the present invention.
These and other objects, features and advantages will become apparent to those of ordinary skill in the art from a reading of the following detailed description and the appended claims. All percentages, ratios and proportions herein are by weight, unless otherwise specified. All temperatures are in degrees Celsius (xc2x0 C.) unless otherwise specified. All documents cited are in relevant part, incorporated herein by reference.